1. Field of the Invention
This invention relates to a blood pressure measuring method, wherein a pulse oscillogram of a patient is determined and the blood pressure is thus detected and displayed, as well as to a sphygmomanometer for executing the method.
2. Discussion of Related Art
A non-invasively measuring blood pressure measuring method, or sphygmomanometer, is disclosed in European Patent Reference EP 1 101 440 A1. With this known method, or device, which is based on an oscillometrically-measuring, automatic method, one or several pulse oscillograms are selectively generated during a blood pressure measuring operation, in order to determine the blood pressure values from it or them, and to display them. In the first mode of operation, a systolic and a diastolic blood pressure value are determined in a manner known per se in one measurement cycle by a single pulse oscillogram. In the second mode of operation it is inter alia determined on the basis of several definite pulse oscillograms, between which a pause of 60 sec. is maintained, whether so-called hemodynamic stability exists. If there is no hemodynamic stability, this is indicated to the user by the output of an error code. Thus the user is informed when the measured blood pressure values have been adulterated because of insufficient hemodynamic stability, in particular insufficient circulatory rest wherein, however, the measuring time is not inconsiderably increased.
A method or device described by German Patent Reference DE 102 18 574 A1 for measuring blood pressure is also designed for detecting arrhythmia, wherein pulse wave information, such as the width, height and a time interval is detected for a plurality of beats. However, with a lack of circulatory rest, the blood pressure values per se cannot not be sufficiently accurately measured.
The lack of circulatory rest is considered to be the most important error influence during an outpatient measurement of arterial blood pressure. Patients doing their own measuring, but even medical specialists, do not possess criteria which are simple to detect during blood pressure measurements in order tojudge circulatory rest. In many cases the length and size of a lack of circulatory rest is underestimated. Lack of circulatory rest has been documented in the course of measurements by physicians as the so-called “white-coat-effect”, inter alia, and is known.